[extropy-chat] Re: SPACE: new planet?
neptune at superlink.net
Sat Feb 21 03:10:26 UTC 2004
On Friday, February 20, 2004 9:21 PM Mike Lorrey mlorrey at yahoo.com
>> Mike Lorrey wrote:
>> >It is actually rather easy to define a planet:
>> >a) it has its own independent orbit around the sun, and,
>> >b) its own internal gravity has caused it to be round
>> What is "round"?
No planet seems perfectly spherical/round, but would you then say Ceres
is a planet? IIRC, it looks round.
Also, can it be said that the Earth has an independent orbit since the
Moon impacts its orbit so much? Certainly, Luna impacts Earth's orbit
much more than any other IAU defined planet's moon(s) save for Pluto.
While I'd still call Earth a planet -- and Pluto too:) -- I see them --
Earth-Luna and Pluto-Charon -- as special cases.
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